title: Skin diseases associated with Malassezia yeasts: facts and controversies.
abstract: The implication of the yeast genus Malassezia in skin diseases has been characterized by controversy, since the first description of the fungal nature of pityriasis versicolor in 1846 by Eichstedt. This is underscored by the existence of Malassezia yeasts as commensal but also by their implication in diseases with distinct absence of inflammation despite the heavy fungal load (pityriasis versicolor) or with characteristic inflammation (eg, seborrheic dermatitis, atopic dermatitis, folliculitis, or psoriasis). The description of 14 Malassezia species and subsequent worldwide epidemiologic studies did not reveal pathogenic species but rather disease-associated subtypes within species. Emerging evidence demonstrates that the interaction of Malassezia yeasts with the skin is multifaceted and entails constituents of the fungal wall (melanin, lipid cover), enzymes (lipases, phospholipases), and metabolic products (indoles), as well as the cellular components of the epidermis (keratinocytes, dendritic cells, and melanocytes). Understanding the complexity of their interactions will highlight the controversies on the clinical presentation of Malassezia-associated diseases and unravel the complexity of skin homeostatic mechanisms.
authors.affiliation: Department of Skin and Venereal Diseases, University of Ioannina Medical School, Ioannina, Greece. Electronic address: ggaitan@cc.uoi.gr.
authors.forename: Georgios
authors.initials: G
authors.lastname: Gaitanis
authors.affiliation: Mycology Laboratory, Microbiology Department, Medical School, National and Kapodistrian University of Athens, Athens Greece.
authors.forename: Aristea
authors.initials: A
authors.lastname: Velegraki
authors.affiliation: Department of Dermatology and Andrology, Justus Liebig University Giessen, Giessen, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Mayser
authors.affiliation: Department of Skin and Venereal Diseases, University of Ioannina Medical School, Ioannina, Greece.
authors.forename: Ioannis D
authors.initials: ID
authors.lastname: Bassukas
mesh_terms: D003881:Dermatomycoses / Q000382:microbiology*; D006706:Homeostasis; D006801:Humans; D008290:Malassezia / Q000145:classification* / Q000302:isolation & purification; D012867:Skin / Q000382:microbiology*